This PhD thesis presents a geological and geophysical study that characterizes the Quaternary stratigraphy, geomorphology, recent tectonics, and discusses their implications to understand the geodynamic evolution of North Tunisia, including the emerged land and continental margin. The study area spans much of the region containing the boundary between the African and Eurasian tectonic plates in this sector. The onshore main structural pattern strikes in a NE-SW trend that extends offshore, into the North Tunisian continental margin plateau that is part of the same recent deformation system. I have carried out specific analyses of these two onshore and offshore regions where present-day tectonics has been previously poorly studied. Although some limited activetectonic studies had been carried out onshore, the offshore area was scarcely studied to date, and never explored in the detail presented in this work, let alone studied in an onshore-offshore integrative study. To carry out the joint study of the two regions we have had to take different methodological approaches.
Onshore Northern Tunisia we applied a morphometric relief analysis of digital elevation models based in drainage network metrics to characterize active tectonics and its influence into the drainage evolution of the area. This analysis was ground-truthed with a field campaign in March 2015 to examine the several morphometric anomalies obtained with the relief analysis carried out before. Our analysis indicates that recent river captures have been the main factor driving the fluvial network reorganization in Northern Tunisia. Morphometric indices evidence fluvial network reorganization that indicates that the catchment area of the Medjerda River has increased through time by capturing adjacent axial valleys to the east of its previous drainage divide. These captures are probably driven by the gradual uplift of adjacent axial valleys by reverse/oblique slip faults like El Alia-Teboursouk and Dkhila faults or associated folding. Our fieldwork discovered that these faults cut Pleistocene sediments and possible associated coseismic structures were identified, further supporting recent fault activity with estimated maximum magnitudes (Mw) of 6.7 and 6.5 respectively for each fault. [...]